U.S. Pat. Nos. 5,013,806; 5,077,365; and 5,071,932 (issued to Blevins and Turner in 1991) disclose copolymers of 4-vinyl-1,3-dioxolane with maleic anhydrides. Other than the compounds and processes described in these commonly-owned patents, no other known reference discloses copolymers of a 4-vinyl-1,3-dioxolane with maleic anhydride or its derivatives. While the copolymers of Blevins and Turner are useful, it would be desirable to have copolymers that are more resistant to moisture and hydrolysis.